When Morse is on the skid pan, he can't find the switch to operate the windscreen wipers but when he is attacked there are 3 external shots of the car. In the first the wipers are off. In the second they are working, and then they are off again.
When Angela brings in the cannabis plants that apparently Jeremy has been forcing her to grow for him, no-one seems to be arrested. In Britain cannabis has been illegal as a recreational 'grow your own' drug since 1928.